This simulation shows the beats that occur when two waves of different
frequencies interfere with each other. The two individual waves are shown
in green and blue, while their sum is shown in red. When you listen to
beats you should understand that you're not hearing sound at that
frequency (2 Hz is well below the range of human hearing, for instance),
but you're hearing the intensity of the sound rising and falling at the
beat frequency. Here are some things to investigate:

1.

The interference of waves is critical for understanding beats. Look carefully at the individual waves to see how they interfere to create the typical rising and falling beat pattern.